This invention relates to torque screws of the type generally used to attach an object to a panel or frame wherein it is desired to limit the torque the screw may place on either the object or frame such that potential damage caused by over tightening the screw is eliminated.
Various requirements in manufacturing and assembly of components have dictated the need for a screw fastener that cannot be over tightened such that damage to panels or other object to which the fastener is attached does not occur. Various torque limiting screws exist in the prior art, including U.S. Pat. No. 5,120,168 to Padula, and U.S. Pat. No. 4,109,691 to Wilson, each of which is a "single use only" screw which provides tamper resistance, but here, once the screw is installed, it cannot easily be unscrewed. U.S. Pat. No. 4,472,098 to Kiefer is an invention for a torque limiting nut that uses an elastomeric material to engage a threaded screw shaft. None of these patents disclose a torque screw that allows reuse an indefinite number of times and allows the screw to be unscrewed in a normal manner.
Additionally, none of these torque screws is of a captive screw style.
Finally, it would be advantageous to have an audible signal indicating that the torque screw has reached its predetermined torque limit. It is not believed that any screws of the present type have this audible feature.